Fun

July 18, 2016

He's been called "The Picasso of pumpkin carving" and his pumpkins are stunningly spectacular, but Ray Villafane is also a remarkable sand sculptor. His “Elephant and Mouse,” created in collaboration with Long Island-based artist Sue Beatrice, is now on view at Arizona's Carefree Desert Gardens (Arizona is a lovely place - Villafane lives in Surprise, which is not far from Carefree, both just north of Phoenix).

From Phoenix magazine (which anoints Villafane as "the Sendak of sand sculpture"):

The sand sculpture depicts an elephant playing chess with a mouse, and is striking with its life-size scale and details, like the tiny hairs on the elephant’s head, eyelashes and tail (made from palm frond fibers), and tree rings in the stump. A bulging bag of peanuts lies to one side, with some spilling out of the sack and one that appears to be floating in midair, as if falling from the elephant’s mouth. “It’s magic,” Beatrice says, before pointing to a small stick connecting the elephant and the peanut. “[Ray] is over the top, and he can do anything. In addition to his artistic talent, he’s great at creative problem-solving. That’s just one example.”

June 24, 2015

Our planet’s deserts are sweeping landscapes of variety and diversity, human and otherwise. But if you are looking for imagery of the desert as desolate and threatening, then the new Mad Max movie will do the trick – in spades. "Our world is fire and blood" declares one of the characters, and indeed it is, crammed with deranged creatures, bizarre weaponry, and outrageous vehicles (plus diaphanously dressed young women), all of them in virtually non-stop action, most of which, incredibly, is real as opposed to CGI.

My reason for seeing Mad Max – Fury Road was, of course to see the desert and the geology, but the pace and drama of the film made it seriously difficult to focus on the background scenery. That scenery was originally (this film has been a very long time in the making) supposed to be Australian, the locations planned around the outback mining town of Broken Hill. But the desert did not co-operate: rains came and the post-apocalyptic setting was festooned with wildflowers, creating an ambience deemed inappropriate. The whole production then switched to Namibia and the stunning arid landscapes inland from Swakopmund. Stunning locations and stunning film-making (the jury is, however, still out in terms of the environmental consequences).

I have to say that I enjoyed this Mad Max immensely – I was looking for entertainment rather than intellectual challenge and it most certainly delivered. Herewith, a few of the items I found particularly entertaining – no spoilers, just screen-grabs taken from the trailers on the movie’s website, plus a little commentary.

The scene of Max emerging from being violently buried in the sand is extraordinary – it begins in such a way that the viewer’s sense of scale is completely lost – what are we looking at? It’s only as Max emerges that we become aware.

The mother of all sand/dust-storms, from which, of course, the key characters emerged unscathed – along with their vehicles.

And those vehicles are, in many ways, the stars. Huge and malevolent, inventive and monstrous steam-punk cannibalizations of vaguely recognisable trucks and cars with decayed post-apocalyptic industrial kitchen equipment and weaponry – plus music. The “Doof Wagon” is perhaps the most eccentric, a gigantic hurtling stage crammed with amps and sub-woofers, the crazed blind Doof Warrior strapped to the front with bungee cords, his enormous guitar doubling as a flame-thrower.

At the back of the Doof Wagon are huge drums, whose crazed players beat out the rhythm of war and violence. Oh, and the makings of a brass band – in the final scene of fire and mayhem as the Doof Wagon comes to a violently disintegrating end, I was delighted, in the lower right of the screen to see a tuba tumbling through the air.

Our heroes’ means of transport is the War Rig, fully equipped with a cow-catcher. Although no cows remain on the planet, this comes in handy as a sand-plough to extinguish another raging fire.

No desert is complete without its salt-pans, quagmires after inundation, and, inevitably the War Rig becomes bogged down in the mud and the gloom. I was reminded of Isabelle Eberhardt’s description of the great salt lakes of Tunisia, the chotts:

treacherous expanses where a thin, apparently dry crust hides unfathomed pits of mud . . . And beneath the motionless crystal of the salty waters there are countless archipelagos of clays and multicoloured rocks, in perpendicular and stratified ledges . . . a labyrinth of deep canals, islets, pitfalls, of deposits of salt and saltpetre . . . a leprous region where all the earth’s secret chemistries are on display in the bright sun . . . An inchoate sadness hangs over this lonely region ‘from which God has withheld his blessing’, a vestige, perhaps, of some forgotten Dead Sea, with nothing to boast of but bitter salt, sterile clay, saltpetre and iodine.

It almost seemed as if Mad Max had employed Eberhardt as a script-writer.

As, once again, all seemed lost in the inchoate sadness and desperation, a lone tree miraculously appears in the mist. The poor tree allows the rig to be winched out of the mire, but at the cost of its own destruction.

It makes me wonder whether the true story of the lone Saharan Tree of Tenere, supposedly knocked down by a drunken truck-driver, could possibly be that Mad Max came by…

There is spectacular geology to be seen in the movie, but it does hurtle by at a bewildering rate – as does everything. But it is an incredible and highly-recommended super-charged experience.

January 17, 2015

No, it's not alien art. A robotic beach artist has created giant drawings in the sand. Developed by Paul Beardsley from Disney Research Zurich and his colleagues at the Swiss Federal Institute of Technology, the wheeled robot can recreate a drawing sent to it from a phone or tablet.

It computes a path across the sand that approximates the artwork and sets off. A rake attached to its rear etches the pattern in the sand. Each drawing takes about 10 minutes, and the idea is that the robot could be controlled remotely, turning the beach into a digitally controlled sketchbook.

Since the robot moves on three wheels, it is better at creating smooth curves rather than sharp corners. To carve a right angle in the sand, it draws a line then lifts the rake, before using a laser scanner and an inertial sensor to reposition itself so it can trace the intersecting line.

The team plans to equip the robot with a range of tools so that it can imprint a variety of textures or erase previous markings, and is also taking inspiration from the Nazca Lines – ancient motifs produced in the Nazca desert in Peru. "We would like to make huge sand art that amazes people," says Beardsley.

The robot was presented at Techfest in Bombay, India, in late December.

December 23, 2014

August 13, 2012

I do, on occasion – and to the great distress of anyone within earshot – quite literally blow my own trumpet. Or, to be precise, these days, a flugelhorn. It began in the early Pleistocene when I was in high school, playing second trumpet in the band and orchestra to the first, whose surname, gloriously, was “Tootle.” I graduated – to the great distress of anyone within earshot - to the tuba (a fine and much-maligned instrument), and my father always maintained, entirely erroneously, that this was simply because the size of the instrument required my being driven to school on rehearsal days.

But enough of my instrumental aspirations (as anyone within earshot would agree). There’s always a great and immodest pleasure in finding oneself cited, and there have recently been several examples of this, to which I feel compelled to draw attention. First of all, Andrew Alden on About Geology kindlyposted a reprise of his views on Sand, together with a link to the conversation he and I had a couple of years ago. Then Gary Hayes at Geotripper referred to “an excellent geo-blog based on sand” in his recent post, “Sand...Lots of Sand.”

And, just yesterday, Geoff Manaugh, of the acclaimed BLDBLOG, put up two successive posts directly related to topics that I have written about – the New York sand mines, and the Normandy beaches (see the posts, in addition to sections in the book, here, and here).

So thanks to all for the citations and the pleasure. I shall now sign off, without – to the relief of those within earshot – fanfare.

Update 14 August, breaking news! Thanks to Geoff Manaugh and BLDBLOG, I have now made it onto BOINGBOING.

August 09, 2012

Before you head off to the beach, you might want to jot down the equation in the image above. Because this is good news for sandcastle builders. Had you been depressed by the fact that science can easily demonstrate that the maximum height of a sandcastle is 20 cms (assuming you believe that what’s going on is driven by capillary forces), then you should celebrate the news that new science now allows for sandcastles several meters high. But then again, your own kids have probable demonstrated that elevations of significantly more than 20 cms are no problem at all, never mind the stark evidence of the towering sand sculptures routinely constructed in events around the world. Those capillary guys really need to get out of the lab, look around occasionally at reality, and get a life.

A just-published report from Nature, playfully titled “How to construct the perfect sandcastle,” is a work of serious science, and one of those delightful international collaborations between researchers, in this case from Iran, the Netherlands, and France.

The challenges that dry granular materials pose to science are seemingly endless, and have been reported on this blog too often to link here (just put “granular” into the search box for a sampling). But wet granular materials represent depths still unchartered by physics, and the act of building a sandcastle is the quintessential illustration of this – just add water to dry sand, and it becomes an entirely new and different material. Add more water and everything changes yet again (no wonder that researchers are trying to develop phase diagrams – like those for ice, water, and steam – for granular stuff). This recent work has taken a simple, ground-upwards (so to speak) approach to the mechanisms of sandcastle stability:

To account for the (in)stability of sandcastles, we show here that it is sufficient to consider that the limit of instability is reached when a column of sand undergoes a buckling transition under its own weight. An elastic rod becomes elastically unstable and buckles under its own weight when exceeding a critical height.

This, of course, again reflects real experience – adding that last bucket of sand to the top of the castle causes the whole thing to collapse, tragically and infuriatingly. There’s a standard equation for the maximum height of a cylinder before it buckles under its own weight that incorporates its radius and density, gravity (inevitably), a rather esoteric term that, quite frankly I don’t understand, and, critically, the elastic modulus of the material. This latter characteristic is critical – also known as Young’s Modulus, it describes how strong a material is, how well it responds to strain. In this case the strain is its own weight, and the strength of wet sand comes entirely from the surface tension effects of just a little water between the grains.

I sometimes use a dramatic demonstration of the potency of surface tension – simply wet a number of ping-pong balls, cluster them together, and see how many you can drag across the surface of a table by just pulling one of them. It’s surface tension that allows us to build a sandcastle, that gives the wet sand its strength. For physicists, the reality of exactly what’s going on between the grains is somewhat more complex, but the authors of this paper have taken the model for the strength of wet granular matter and worked it to develop an equation for the optimum strength, or elastic modulus. Plug that back into the equation for the maximum height of a cylinder, and you end up with the wonderful expression for “h,” the maximum height of a sandcastle, in the image above. The researchers then tested this by making their own cylinders of sand with varying diameters, and found that reality correlated well with prediction:

"To verify this experimentally, beach sand with an average radius of 100 mm was mixed with a small amount of deionized water. Cylindrical ‘sandcastles’ were constructed using non-wetting PVC pipes of different diameters cut in half over the length of the tube. The two halves were assembled, and the wet sand was put in the tube standing on vertically on a surface. The wet sand was poured into the pipe in small portions and compacted by dropping a thumper into the pipe at least 70 times. This process was repeated until the pipe was filled with sand up to a certain height. The two halves of the cylindrical tube were then carefully removed and if the sand column was stable, a new experiment was launched filling the tube to a larger height, until the column collapsed. Several experiments were done at each filling height to ensure the reproducibility of the results. Figure 1 shows two columns of sand with height 27 cm and 60 cm with diameters 2 cm and 7 cm. This procedure was followed for 8 pipes of diameter ranging between 0.5 and 7.5 centimeters."

As they note, the compaction is critical. Look at the equation in the image at the head of this post – in order to maximise the height, h, of your sandcastle, you don’t have a lot of options. You can increase the radius of the base (“R”), but can’t do much about gravity (“g”), the size of the grains (“a”), or the density of your mixture (“ρ”), but that mysterious little “α” is, as the authors remark, a “potent power.” And α is a measure of how strong the bonds are between the grains – compact the sand and this increases, and therefore, very importantly, so does the potential height of your castle. The sand sculptors of the world are very well aware of how critical compaction is to their art.

Larry Nelson is a sand sculptor based in Venice Beach, California, and his work is extraordinary. Larry was of enormous help to me when I was writing the Sand book, and he achieves forms with sand that seem impossible: fragile soaring arches, interlocking curves.To achieve these exquisite results, he has developed an intimate relationship with his material, and his description of the character of wet sand eloquently summarizes its magic – and its physics:

It doesn’t take long to learn that water mixed with sand changes both completely. Two fluids become a formable solid. It may be counterintuitive, but anyone who has spent time in the playground knows this in the fingers.

Water tends to pull in on itself. This makes raindrops, rainbows, and flying sparks from every sprinkler. Anything in contact with the water feels this pull, imparting a tiny tensile characteristic to damp sand. It sticks together.

This adhesion is the essence of sand sculpture. It’s also the bane, because damp sand stickily resists being compacted beyond a certain point, no matter how hard it’s hit. Granular materials naturally form arch structures, tiny but powerfully resistant to compaction. Smack it on top, and your pile simply spreads sideways.

Here is just a sample of Larry’s wonderful creations – and note the compacted layers:

So, take the equation to the beach, be inspired by Larry Nelson, look after your radius, and make sure you maximise your alpha. Oh, and I almost forgot – the researchers found that “the optimum strength is achieved at a very low liquid volume fraction of about 1%” – you need 99% sand and just a very little water.

[The paper from Nature: Pakpour, M., Habibi, M., Møller, P. & Bonn, D. How to construct the perfect sandcastle. Sci. Rep. 2, 549; DOI:10.1038/srep00549 (2012). Thank you, Jan Kirchner, for pointing me to it and to Andrew Dwyer, my fearless Outback leader, for bringing the article about it in the Australian Geographic to my attention. Sand sculpture image at the head of the post from the Sand Castle Days 2006 event on South Padre Island, photographed by Sam on the Poof’n’whiffs blog.]

July 30, 2012

There's a reason I've been absent for a week or so - our daughter's wedding was on Saturday. You will probably appreciate that this has involved a certain amount of preparational activity that has somewhat distracted me from my blog responsibilities. The event was held in the garden of my in-laws' house outside Philadelphia and was determinedly - and enjoyably - informal (although to say that this does require rather more preparational activity than a formal and professionally organised event is something of an understatement). The photographic record of the day is still being assembled, but above is an illustration of part of the ceremony. But this clearly requires a little explanation as to what exactly is going on.

The American half of our daughter is an East coast girl, her (now) husband is a West coast guy (San Diego, to be exact). So part of the imagery of the ceremony was the union of East and West, and this was celebrated by the couple each taking a vial of sand from, respectively, beaches of the Atlantic and the Pacific - New Jersey's Island Beach State Park, and Sand Diego's Mission Beach - and mixing them into a single container - which is what has just happened in the photo. So, a little excitement, a few logistics, a great party - and a symbolic sand ceremony. Altogether, a good week.

March 08, 2012

I realise that, in the grand panoply of the global blogosphere, this is but a mote of dust, on a scale more diminutive than a grain of fine sand tossed into the vastness of the universe. BUT, if you had asked me, some three-and-a-bit years ago, as I hesitatingly tapped out my first post, to visualise 200,000 visits to this blog, I would have laughed at the preposterosity of such an idea. However, yesterday evening (Jakarta time), the image above appeared on my Typepad dashboard.

I still can’t quite believe it. I know that this milestone is, in large part, the result of repeated visits by a small number of dedicated readers, and to all of you, my eternal gratitude. The remainder of this statistic is made up of the serendipitous visitors – and, should you be one of those who happens on this post and lingers long enough to read it, thank you. It’s a pleasure, for example, to see how the activity drops off during school holidays, leading me to conclude that I am somehow helping someone out with something that they wanted (or at least needed) to know. It’s a periodic fascination to look at the “keywords” analysis that shows me how a particular search term has led someone here – a selection from the last couple of hours:

Coastal tourist complexes

sand grains which have been magnified

You have a 7-minute sand timer and an 11-minute sand timer. How can you use them to cook a piece of…

global sediment discharge

murano glass factory in venice

permo-triassic event

bacillus pasteurii uses

alcanivorax borkumensis oil spill

2004 tsunami

pink coral with tentacles

verkhoyansk mts map

plus, of course, the ever-popular “Andrew Clemens.”

It’s not that I scrutinise and analyse these things on a daily basis, but it’s intriguing, to say the least. So there we are, enough introspection – but all this brings an added dimension to life that I never anticipated, and which is very much appreciated.

November 24, 2011

The following are entirely reputable and independent pieces of advice for managing a safe and environmentally benign holiday culinary process:

Partially frozen turkeys will cause the oil to bubble over, possibly covering the entire deep fryer in flames......If the fryer does bubble over or tip and spill hot oil, get away from it and don’t try dousing it with cold water. Move objects away from the oil and any fire and smother it with dirt or sand. Having a few buckets of these materials on hand helps you stay prepared in case something does go wrong.

Safe disposal of leftover cooking oils: Mix the cooking oils with unscented kitty litter, sawdust or sand to solidify the oil. Dispose of it in the trash. Avoid scented or disinfectant types of kitty litter as they can react with the oil and cause a fire (so ensure that a few buckets of sand are to hand).

A VERY HAPPY THANKSGIVING TO ALL!

August 09, 2011

You live and learn – well, at least I try. And often I don’t even have to try – something I didn’t know (a category that knows no limits) just ups and surprises me. I read in the paper today about the birth of a sand cat (or sand dune cat, otherwise, Felis margarita). I wan't even aware that there were such critters as sand cats, and I certainly didn’t anticipate how damned cute they are. This sand kitten – above, with her mother - has just been born at the Ramat Gan Safari Park near Tel Aviv, Israel. The kitten is the first of the Sand Cat species, considered extinct in Israel, to be born at the safari park. “She has been named Renana and it is hoped that she will join Israel's Sand Cat Breeding Program in order to reintroduce the species back into the wild.” (3news, New Zealand).

Sand cats are so-called because hairs on the soles of their feet have helped them adapt to their desert environment by providing both insulation and traction in the sand; herewith, from the BBC’s “Wildfacts” site:

Sand cat, sand dune catFelis margarita

Like some other desert animals, sand cats are capable of surviving without drinking - they obtain all the water they need through their food.

Physical DescriptionSand cats have a pale yellow, to grey-brown coat, which is slightly darker on the back and pale on the belly. A bold streak runs across each cheek from the corner of each eye.

The tail is ringed with a black tip. Sand cats have a broad head with large eyes and low-set ears. They have short limbs and dense hair on the soles of the feet. The hair on the feet serves to insulate against the intense heat and cold of their habitat, as well as aiding movement across the sand.

HabitatSand cats live in the desert and are adapted to extremely arid terrain.

DietThey hunt rodents and occasionally hares, birds and reptiles. They are apparently able to survive without drinking free water, and obtain the moisture they require from their prey.

BehaviourSand cats are mainly active at night. They are good diggers which helps when hunting for underground prey and for digging the burrow that they rest in during the day.

ReproductionSand cats give birth to 2-4 kittens after a gestation period of 59-63 days. The kittens weigh about 39g at birth.

Conservation statusThe IUCN lists the Pakistani subspecies F.m.scheffeli as Lower Risk. Sand cats are on CITES: Appendix II. They face persecution due to the threat they pose to livestock. F.m.scheffeli was not discovered until 1966 but has declined drastically through uncontrolled commercial dealing.

In a somewhat chaotic week that continues to consume time and mental energy, this has provided a fun (and yet informative) instant post topic. But it also reminds me of the sort of feline meme that went around the geoblogosphere not long ago, wherein photos were contributed of various cats in geologically resonant poses. Not owning a cat these days, I could not contribute, and even my daughter’s feline, Woody, has yet to show even a passing interest in the mineral and rock collection that should attract his limited attention on a daily basis – and hence provide a geofelino photo-op. But what this does do is give me an excuse, with no arenaceous connotations whatsoever, to post my photo of a quintessentially Indonesian cat that I recently found living in a quintessentially Indonesian tree.